The global proliferation of marine artificial habitats is rapidly altering the physical structure of coastlines, with knock-on effects on physical, chemical, and ecological processes at seascape scales. Ecological consequences of maritime sprawl associated with aquaculture are poorly understood, despite the fact that these suspended structures are particularly prone to biofouling, which can affect the industry and seascape around it. We characterised seascape-scale spatial and temporal distribution patterns of 10 biofouling taxa in relation to the presence and distance to Perna canaliculus mussel farms in New Zealand’s largest aquaculture region. Seven of 10 taxa had significantly higher cover on farms than in natural habitats throughout the region. The cover of 4 of those 7 taxa, including the high-profile pests Mytilus galloprovincialis and Undaria pinnatifida, exponentially decreased with distance from the nearest farm, while some taxa were absent from natural habitats (e.g. the ascidian Ciona robusta). In contrast, several opportunistic macroalgal species, such as Cladophora ruchingeri and Pylaiella littoralis, had colonised extensive areas of natural habitat. Our results suggest that biofouling is a persistent issue on mussel farms and that farm structures may act as reservoirs or ‘stepping stones’ for the dispersal of potential marine pests. These distributional and dispersal patterns can inform integrated pest management efforts focusing on spatial management strategies, such as ‘firebreaks’ in farm connectivity, avoidance of pest hotspots, and farm fallowing.

Pests of bivalve aquaculture are a challenging problem that can reduce productivity, profitability and sustainability. A range of pest management approaches have been developed for bivalve aquaculture, but a general absence of guiding frameworks has limited the scale and permanency of implementation. Applying principles of ‘integrated pest management’ (IPM) could change this paradigm to improve economic and environmental outcomes. We reviewed existing research and tools for pest management in bivalve aquaculture, with studies grouped under five pillars of IPM: pest ecology (25 studies), bioeconomic cost–benefits (4 studies), continual monitoring (17 studies), proactive prevention (32 studies) and reactive control (65 studies). This body of knowledge, along with insights from terrestrial agriculture, provide a strong foundation for developing and implementing IPM in bivalve aquaculture. For example, IPM principles have been applied by a regional collective of oyster farmers in the US Pacific Northwest to optimize pesticide application and search for other options to control problematic burrowing shrimps. However, IPM has not yet been broadly applied in aquaculture, and data gaps and barriers to implementation need to be addressed. Priorities include establishing meaningful pest–crop bioeconomic relationships for various bivalve farming systems and improving the efficacy and operational scale of treatment approaches. An IPM framework also could guide potential step‐change improvements through directing selective breeding for resistance to pests, development of bespoke chemical control agents, applying emerging technologies for remote surveillance and farm management, and regional alignment of management interventions. © 2022 Society of Chemical Industry.

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